From: David Brown <dbrown_at_nyahnyahspammersnyahnyah>

Date: Tue Aug 30 2011 - 12:16:06 MDT

Date: Tue Aug 30 2011 - 12:16:06 MDT

Sorry Mike,

Ignore my message. You can't have 2d coordinates as coordinate variables in NetCDF either. Dennis is right.

-dave

On Aug 30, 2011, at 12:11 PM, David Brown wrote:

*> HI Mike,
*

*> Change the lines:
*

*> npp@lat2d=lat2d
*

*> npp@lon2d=lon2d
*

*> to
*

*> npp&lat2d = lat2d
*

*> npp&lon2d = lon2d
*

*>
*

*> You are trying to write 2d variables as attributes, which NetCDF does not allow. NCL should not be seg faulting though. We will look into this.
*

*> -dave
*

*>
*

*> On Aug 30, 2011, at 12:05 PM, Michael Notaro wrote:
*

*>
*

*>> Thanks Dennis. Using hdfeof helps a lot and gives me the lats/lons now.
*

*>>
*

*>> Seems I am having another problem. After I read the hdfeos and retrieve
*

*>> the lats/lons and data, I tried writing it to a file and always get segmentation fault.
*

*>> What am I doing wrong?
*

*>>
*

*>>
*

*>>
*

*>>
*

*>>
*

*>> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
*

*>> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"
*

*>> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"
*

*>> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/shea_util.ncl"
*

*>> begin
*

*>>
*

*>> ; 1km annual npp modis on 1200x1200 tiles
*

*>>
*

*>> a=addfile("/Users/notaro/downloads/Y2000/MOD17A3.A2000366.h11v11.305.2009342143541.hdf.hdfeos","r")
*

*>>
*

*>> lat2d=a->GridLat_MOD_Grid_MOD17A3
*

*>> lon2d=a->GridLon_MOD_Grid_MOD17A3
*

*>>
*

*>> npp=short2flt(a->Npp_1km_MOD_Grid_MOD17A3)
*

*>>
*

*>> npp!0="lat2d"
*

*>> npp!1="lon2d"
*

*>> npp@lat2d=lat2d
*

*>> npp@lon2d=lon2d
*

*>> npp@coordinates="lat2d lon2d"
*

*>> npp@projection="sinusoidal"
*

*>>
*

*>> printVarSummary(npp)
*

*>>
*

*>> out=addfile("test.nc","c")
*

*>> out->npp=npp
*

*>> out->lat2d=lat2d
*

*>> out->lon2d=lon2d
*

*>>
*

*>> end
*

*>>
*

*>>
*

*>>
*

*>>
*

*>>
*

*>>
*

*>>
*

*>> Variable: npp
*

*>> Type: float
*

*>> Total Size: 5760000 bytes
*

*>> 1440000 values
*

*>> Number of Dimensions: 2
*

*>> Dimensions and sizes: [lat2d | 1200] x [lon2d | 1200]
*

*>> Coordinates:
*

*>> Number Of Attributes: 7
*

*>> lon2d : <ARRAY of 1440000 elements>
*

*>> lat2d : <ARRAY of 1440000 elements>
*

*>> _FillValue : 1e+20
*

*>> coordinates : lat2d lon2d
*

*>> hdfeos_name : Npp_1km
*

*>> projection : sinusoidal
*

*>> unsigned : True
*

*>>
*

*>>
*

*>>
*

*>>
*

*>>
*

*>>
*

*>>
*

*>>
*

*>>
*

*>> On Aug 30, 2011, at 12:44 PM, Dennis Shea wrote:
*

*>>
*

*>>> Mike
*

*>>>
*

*>>> [1]
*

*>>> %> ncl_filedump MOD17A3.A2010365.h00v08.305.2011029145245.hdf
*

*>>>
*

*>>> yields
*

*>>>
*

*>>> Variable: f
*

*>>> Type: file
*

*>>> filename: MOD17A3.A2010365.h00v08.305.2011029145245
*

*>>> path: MOD17A3.A2010365.h00v08.305.2011029145245.hdf
*

*>>> file global attributes:
*

*>>> HDFEOSVersion : HDFEOS_V2.16
*

*>>> StructMetadata_0 : GROUP=SwathStructure
*

*>>> END_GROUP=SwathStructure
*

*>>> GROUP=GridStructure
*

*>>> GROUP=GRID_1
*

*>>> GridName="MOD_Grid_MOD17A3"
*

*>>> XDim=1200
*

*>>> YDim=1200
*

*>>> UpperLeftPointMtrs=(-20015109.354000,1111950.519667)
*

*>>> LowerRightMtrs=(-18903158.834333,0.000000)
*

*>>> Projection=GCTP_SNSOID
*

*>>> [SNIP]
*

*>>>
*

*>>> [2]
*

*>>> If you append the '.hdfeos' suffix, you will get that lat/lon values.
*

*>>>
*

*>>> %> ncl_filedump MOD17A3.A2010365.h00v08.305.2011029145245.hdf.hdfeos
*

*>>>
*

*>>> Variable: f
*

*>>> Type: file
*

*>>> filename: MOD17A3.A2010365.h00v08.305.2011029145245.hdf
*

*>>> path: MOD17A3.A2010365.h00v08.305.2011029145245.hdf
*

*>>> file global attributes:
*

*>>> dimensions:
*

*>>> YDim_MOD_Grid_MOD17A3 = 1200
*

*>>> XDim_MOD_Grid_MOD17A3 = 1200
*

*>>> variables:
*

*>>> double GridLat_MOD_Grid_MOD17A3 ( YDim_MOD_Grid_MOD17A3,
*

*>>> XDim_MOD_Grid_MOD17A3 )
*

*>>> projection : (null)
*

*>>> corners : ( 9.995833332438675, 9.995833332438675,
*

*>>> 0.004166666666293064, 0.004166666666293064 )
*

*>>> long_name : latitude
*

*>>> units : degrees_north
*

*>>>
*

*>>> double GridLon_MOD_Grid_MOD17A3 ( YDim_MOD_Grid_MOD17A3,
*

*>>> XDim_MOD_Grid_MOD17A3 )
*

*>>> projection : (null)
*

*>>> corners : ( 177.2297839752788, -172.6245418649626,
*

*>>> -170.00416710093, -179.9958337931229 )
*

*>>> long_name : longitude
*

*>>> units : degrees_east
*

*>>> [snip]
*

*>>>
*

*>>> [3] Use the hdfeos suffix. The names are different than using 'just' hdf
*

*>>> however NCL does provide the georeferenced data coordinates.
*

*>>>
*

*>>>
*

*>>> [4] You might look at:
*

*>>>
*

*>>> http://www.ncl.ucar.edu/Applications/binning.shtml
*

*>>>
*

*>>> Good luck
*

*>>> D
*

*>>>
*

*>>>
*

*>>>
*

*>>>
*

*>>> On 8/30/11 11:23 AM, Michael Notaro wrote:
*

*>>>> I am trying to work with MODIS HDF data of the land variable 1-km annual NPP (net primary productivity).
*

*>>>>
*

*>>>> ftp://ftp.ntsg.umt.edu/pub/MODIS/Mirror/MOD17_Science_2010/MOD17A3/
*

*>>>>
*

*>>>> Each file is on a separate tile. I put the info below on a sample file's
*

*>>>> info on the variable Npp_1km and the 1200x1200 grid and bounding rectangle.
*

*>>>>
*

*>>>> It is my understanding that I should grab the rectangles that overlap my study region,
*

*>>>> which is Wisconsin. I think 4 of them overlap it.
*

*>>>>
*

*>>>> I can read in the data with addfile (or use ncl_convert2nc). But I am not sure
*

*>>>> how to retrieve the proper lats/lons to plot the data correctly. I used short2flt also
*

*>>>> when reading it. I am guessing that the data grid must not be a normal rectangle but
*

*>>>> stretched as the satellite moves, since the range of the lats is 10 degrees but the
*

*>>>> range of the lons is 60 degrees.
*

*>>>>
*

*>>>> Any suggestions on how to plot this in NCL is appreciated.
*

*>>>>
*

*>>>> Michael
*

*>>>>
*

*>>>>
*

*>>>> YDim_MOD_Grid_MOD17A3 = 1200 ;
*

*>>>> XDim_MOD_Grid_MOD17A3 = 1200 ;
*

*>>>>
*

*>>>> short Npp_1km(YDim_MOD_Grid_MOD17A3, XDim_MOD_Grid_MOD17A3) ;
*

*>>>> Npp_1km:hdf_name = "Npp_1km" ;
*

*>>>> Npp_1km:units = "kg_C/m^2" ;
*

*>>>> Npp_1km:long_name = "MOD17A3 NPP--MODIS Gridded 1KM Annual Net Primary Productivity (NPP)" ;
*

*>>>> Npp_1km:_FillValue = -1s ;
*

*>>>> Npp_1km:valid_range = 0s, -36s ;
*

*>>>> Npp_1km:calibrated_nt = 23 ;
*

*>>>> Npp_1km:add_offset_err = 0. ;
*

*>>>> Npp_1km:add_offset = 0. ;
*

*>>>> Npp_1km:scale_factor_err = 0. ;
*

*>>>> Npp_1km:scale_factor = 0.0001 ;
*

*>>>>
*

*>>>> " OBJECT = NORTHBOUNDINGCOORDINATE\n",
*

*>>>> " NUM_VAL = 1\n",
*

*>>>> " VALUE = 69.9999999937138\n",
*

*>>>> " END_OBJECT = NORTHBOUNDINGCOORDINATE\n",
*

*>>>> "\n",
*

*>>>> " OBJECT = SOUTHBOUNDINGCOORDINATE\n",
*

*>>>> " NUM_VAL = 1\n",
*

*>>>> " VALUE = 59.9999999946118\n",
*

*>>>> " END_OBJECT = SOUTHBOUNDINGCOORDINATE\n",
*

*>>>> "\n",
*

*>>>> " OBJECT = EASTBOUNDINGCOORDINATE\n",
*

*>>>> " NUM_VAL = 1\n",
*

*>>>> " VALUE = -119.983333303015\n",
*

*>>>> " END_OBJECT = EASTBOUNDINGCOORDINATE\n",
*

*>>>> "\n",
*

*>>>> " OBJECT = WESTBOUNDINGCOORDINATE\n",
*

*>>>> " NUM_VAL = 1\n",
*

*>>>> " VALUE = -179.999999938971\n",
*

*>>>> " END_OBJECT = WESTBOUNDINGCOORDINATE\n",
*

*>>>> "\n",
*

*>>>>
*

*>>>> _______________________________________________
*

*>>>> ncl-talk mailing list
*

*>>>> List instructions, subscriber options, unsubscribe:
*

*>>>> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
*

*>>> _______________________________________________
*

*>>> ncl-talk mailing list
*

*>>> List instructions, subscriber options, unsubscribe:
*

*>>> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
*

*>>
*

*>> _______________________________________________
*

*>> ncl-talk mailing list
*

*>> List instructions, subscriber options, unsubscribe:
*

*>> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
*

*>
*

*> _______________________________________________
*

*> ncl-talk mailing list
*

*> List instructions, subscriber options, unsubscribe:
*

*> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
*

_______________________________________________

ncl-talk mailing list

List instructions, subscriber options, unsubscribe:

http://mailman.ucar.edu/mailman/listinfo/ncl-talk

Received on Tue Aug 30 12:16:13 2011

*
This archive was generated by hypermail 2.1.8
: Wed Sep 07 2011 - 10:58:58 MDT
*